The top-secret capture of a Nazi submarine just two days before D-Day

U-505 Submarine

The German submarine crew thought they were about to die. Their U-boat was sinking, American ships were closing in, and depth charges were exploding all around them. Then something crazy happened on June 4, 1944.

Instead of letting U-505 sink, the Americans decided to steal it. Captain Daniel Gallery ordered his men to board the enemy vessel, making naval history because no enemy warship had been captured at sea since 1812.

Here’s how they did it, and how you can visit the actual submarine at Chicago’s Museum of Science and Industry.

Task Group 22.3 Hunts for U-boats

The Navy created special “hunter-killer” groups in 1944 to find and sink German submarines. Task Group 22.3 was led by Captain Daniel Gallery aboard the aircraft carrier USS Guadalcanal.

Five smaller ships called destroyer escorts joined the carrier: USS Pillsbury, Pope, Flaherty, Chatelain, and Jenks. They left Virginia on May 15.

Navy codebreakers told Gallery that German submarines were operating near Africa. His ships searched for two weeks using special equipment that could detect radio signals.

Captain Gallery Creates a Plan

Gallery watched another German submarine sink in April 1944. He thought: “What if we could capture one instead?”

Before leaving port, Gallery gathered his officers and shared his idea. They would try to capture a submarine rather than destroy it.

Every ship prepared special boarding teams. Sailors practiced how to take control of an enemy vessel quickly. The plan was simple: use weapons that would force the crew to abandon ship without sinking it. Then send in boarding parties to take control.

Finding U-505

At 11:09 AM on June 4, the USS Chatelain detected something underwater. The sonar operator reported a contact 800 yards away.

Gallery ordered his aircraft carrier to move clear of the area. He sent two fighter planes to watch from above.

Chatelain moved toward the contact but passed over it too quickly for depth charges. Instead, they fired “hedgehogs” – small explosives that detonate when they hit a submarine. The crew prepared for another attack pass, ready to drop their most powerful weapons.

U-505 Comes to the Surface

Chatelain dropped depth charges – barrel-shaped explosives that sink and explode underwater. The blasts damaged U-505’s steering system and flooded rear compartments.

Unable to control his submarine, German commander Harald Lange ordered an emergency surface. The submarine rose from the depths. American ships immediately opened fire.

They used small-caliber guns to keep German sailors away from their deck weapons. Seeing their damaged submarine taking fire, the German crew began abandoning ship. They jumped into the ocean as their vessel continued moving in circles.

The Order to Board

Gallery watched German sailors leaving their ship. At 11:26 AM, just 16 minutes after spotting the submarine, he ordered all ships to stop firing.

Then Gallery issued a historic command: “Away all boarders!” No American captain had given this order since the War of 1812. USS Pillsbury lowered a small boat into the water.

Eight volunteers prepared to board the enemy submarine that was still moving in circles. The mission was extremely dangerous. The submarine might be booby-trapped or sink at any moment.

Lieutenant David Boards First

Lieutenant Albert David led the boarding party from USS Pillsbury. His small boat raced toward the circling submarine. The U-505 moved at about six knots in an erratic circle, making boarding difficult.

David and his men timed their approach carefully. David jumped aboard first, followed by two sailors. They climbed down through the conning tower into the submarine.

No one knew what awaited them below. Armed Germans might be hiding, or explosives might be set to destroy the vessel.

Stopping the Sinking

Inside, the boarding party found water rushing in. The Germans had opened valves to sink their submarine before abandoning it.

David’s men worked quickly in the rising water. Some searched for open valves while others looked for explosives.

They found and closed a main valve, slowing the flooding. The submarine was saved from sinking. The Americans didn’t find all the explosives. One remained armed and hidden, but fortunately never detonated.

Finding Secret Codes

While some sailors stopped the flooding, others gathered important materials. They found code books and secret documents throughout the submarine.

The boarding party discovered two Enigma machines. These special typewriter-like devices created coded messages that the Germans thought were unbreakable.

Sailors collected about 900 pounds of secret materials. Everything went into waterproof bags for transfer to the American ships. These items helped Allied forces track and sink other German submarines, saving countless ships and lives in the Atlantic.

Towing the Prize

With U-505 secured, the Americans needed to move it. USS Pillsbury tried to tow the submarine but its damaged rudder made this difficult.

After several collisions, they tried a different approach. USS Guadalcanal sent more sailors led by Commander Earl Trosino, their chief engineer. Trosino found a clever solution.

As the submarine was towed, its propellers turned in the water. This generated electricity to power pumps that removed water from inside. The dangerous work continued for three days as they prepared for the long journey back to an Allied port.

Journey to Bermuda

After initial repairs, U-505 was transferred to the USS Abnaki, a special towing ship. They began the 1,700-mile journey to Bermuda. The trip took two weeks.

They arrived at the American naval base on June 19, 1944. Everything about the capture remained top secret. If the Germans learned their submarine had been captured with code machines intact, they would change all their codes.

This would have hurt the ongoing invasion of Europe, which had begun just two days after the capture.

Visiting Griffin Museum of Science and Industry

You’ll find U-505 at the Museum of Science and Industry in Chicago at 5700 S. DuSable Lake Shore Drive in Chicago. The main exhibit includes access to the submarine exterior and surrounding artifacts.

For the full experience, purchase the optional on-board tour that takes you inside the actual submarine. The museum offers accessibility accommodations, though the interior submarine tour involves stairs and narrow passages.

Read More from WhenInYourState.com:

• A Prophet’s Murder Triggered the Largest Religious Migration From This Illinois River Town
• This Illinois Village Shows Exactly How Abraham Lincoln Lived Before He Became President
• America’s First Black-Founded Town Challenged Slavery from the Illinois Frontier in the 1830s